Multi-piston release system for a vehicle brake device and brake device for a vehicle gearbox assembly with the multi-piston release system

Description

[0001] The invention relates to a multi-piston release system for a brake device of a vehicle with the features of the preamble of claim 1 and a brake device for a transmission arrangement of a vehicle with the multi-piston release system.

[0002] Piston release systems for actuating clutches or brakes in an electric powertrain of a vehicle are well known from the prior art. For example, German patent application DE 10 2020 104 771 A1 describes a slave cylinder for a vehicle release system with a housing that forms a pressure chamber and with a piston that is axially movable within the pressure chamber. To actuate a clutch, the piston can transmit an actuating force to the clutch. German patent application DE 10 2017 120 250 A1 discloses a slave cylinder system for disengaging a dual clutch, in which a central cylinder is surrounded by several outer cylinders. Further prior art is mentioned in German patent application DE 20 2018 104 092 U1.

[0003] The object of the invention is to design a ring housing for the multi-piston release system that is functionally reliable and cost-effective to manufacture. This object is achieved by a multi-piston release system for a vehicle brake assembly with the features of claim 1 and by a brake device for a vehicle transmission assembly with the multi-piston release system with the features of claim 9. Preferred or advantageous embodiments of the invention are described in the dependent claims, the following description, and the accompanying figures.

[0004] The invention relates to a multi-piston release system designed for actuating a braking device, wherein the braking device is a component of a braking system for a vehicle's transmission assembly. For example, the braking device is a wet multi-disc service brake that can be or is arranged within a wet compartment of an electric or hybrid vehicle. The vehicle is preferably an electric vehicle, in particular an electrically or hybrid-powered passenger car or commercial vehicle.

[0005] The multi-piston release system comprises a ring housing. The ring housing has a main axis that defines an axial direction. The ring housing is, in particular, arranged coaxially and / or concentrically to the main axis.

[0006] The ring housing comprises several housing sections and several pressure chambers that can be filled and / or are filled with a fluid, in particular a hydraulic fluid. A pressure chamber is arranged in each housing section, in particular integrated into and / or formed within the housing section.

[0007] The annular housing has one, preferably exactly one, flow channel. The pressure chambers are fluidically connected to each other via the flow channel. Preferably, the annular housing includes a fluid inlet through which the fluid can be introduced into the flow channel and from there flow into the pressure chambers.

[0008] The multi-piston release system comprises several hydraulic actuation assemblies with multiple piston assemblies. For example, the multi-piston release system includes four, six, or eight actuation assemblies and / or piston assemblies. In particular, the actuation assemblies are arranged at regular intervals around the ring housing in the direction of rotation. An advantage is that the ring housing and the resulting ring-shaped arrangement of multi-piston release systems can be integrated into the brake assembly in a space-saving manner.

[0009] Each actuating assembly is assigned a housing section of the ring housing. Each actuating assembly comprises a piston assembly with a piston. The piston is arranged to be axially movable within the pressure chamber. When hydraulically pressurized, the piston can execute an actuating stroke to introduce an actuating force into the braking device. In particular, during and / or after the execution of the actuating stroke, the piston introduces a compressive force as an actuating force into a friction plate assembly of the braking device, wherein the friction plate assembly comprises a plurality of friction plates. The actuating force presses the friction plates together to generate a braking force.

[0010] Preferably, each actuating arrangement comprises a spring assembly which includes a return mechanism. Preferably, the return mechanism is configured to return the piston in the opposite axial direction. In particular, the piston performs a return stroke when it is returned by means of the return mechanism.

[0011] According to the invention, the ring housing is formed in two parts in the axial direction. It comprises a main housing as a first part and a housing cover as a second part. Preferably, the main housing and the housing cover are annular and / or formed as a closed ring. In particular, the main housing and the housing cover can be arranged axially one on top of and / or one behind the other, and especially assembled.

[0012] In a preferred embodiment of the invention, the main housing comprises the flow channel. Preferably, the flow channel is arranged in or on the main housing, in particular by machining, for example. Optionally, the main housing additionally comprises the housing sections. Preferably, the housing sections are arranged in or on the main housing; in particular, the housing sections are formed by the main housing, specifically integrated into it as a single piece and / or of a single material.

[0013] Another preferred embodiment of the invention provides that the flow channel is arranged in a parting plane between the main housing and the housing cover. Arranging the flow channel in the parting plane has the advantage of easy access, allowing the flow channel to be integrated into the main housing, and in particular, manufactured, in a cost-effective manner. Specifically, this avoids the complex and expensive manufacturing of the flow channel using radial bores drilled into a one-piece ring housing and sealed at the ends with sealing elements.

[0014] According to the invention, the flow channel is annular and / or designed as a circumferential, closed ring. The flow channel is arranged concentrically and / or coaxially to the main axis. The annular design of the flow channel has the advantage that it does not need to be closed by means of the closure elements.

[0015] Another possible design implementation of the invention provides for several axial bores arranged in the main housing, in particular those incorporated into it. Preferably, the axial bores connect the flow channel to the pressure chambers in the housing sections of the main housing. In particular, at least one axial bore runs between the flow channel and one of the pressure chambers. Specifically, the axial bores are drilled through the flow channel and open into the pressure chambers.

[0016] In a preferred embodiment of the invention, the multi-piston release system comprises at least one channel seal, which is designed and / or arranged to seal the flow channel. Optionally, the at least one channel seal is arranged in or on the main housing. Alternatively, the at least one channel seal is arranged on the housing cover. For example, the at least one channel seal is designed as at least one O-ring, preferably as a first and a second O-ring. It is also possible, however, for the at least one channel seal to be arranged between the main housing and the housing cover. In this arrangement, the at least one channel seal is preferably designed as, for example, an annular sealing plate.

[0017] Another preferred embodiment of the invention provides that the housing cover has at least one annular groove for the at least one O-ring, preferably an inner annular groove and an outer annular groove for the first and second O-rings. Alternatively, the main housing can have the at least one annular groove, in particular the inner annular groove and the outer annular groove. This has the advantage that the housing cover does not need to be machined to provide the at least one annular groove. The housing cover can therefore, for example, be designed as a cost-effective sheet metal blank. It is particularly preferred that the at least one O-ring is arranged in the at least one sealing groove.

[0018] For example, the at least one annular groove is arranged concentrically and / or coaxially with respect to the main axis and / or the annular flow channel. Preferably, the outer annular groove extends radially outside the flow channel, radially surrounding the flow channel. Preferably, the inner annular groove extends radially inside the flow channel, with the latter radially surrounding the inner annular groove.

[0019] If the at least one channel seal is designed as the at least one sealing plate, it is preferably arranged in the parting plane, in particular between the main housing and the housing cover. In the configuration as the annular sealing plate, it is preferably arranged coaxially and / or concentrically to the main axis and / or to the main housing and / or to the housing cover.

[0020] In a further preferred embodiment of the invention, the main housing and the housing cover are connected to each other by a positive and / or non-positive connection. For example, the main housing and the housing cover are screwed together. This allows the at least one channel seal to be positively secured. Furthermore, this allows the hydraulic pressure to be generated and maintained in the pressure chambers.

[0021] In a preferred embodiment of the invention, each actuating arrangement comprises a retaining plate. Preferably, the retaining plate is mounted axially onto the housing section of the respective actuating arrangement. In particular, the retaining plate is connected to the housing section by a force-fit and / or positive-locking connection, for example, by being screwed to it.

[0022] In one possible embodiment of the invention, the spring assembly comprises a spring plate, a spring retainer, and a coil spring. Preferably, the spring retainer is positively and / or frictionally connected to the spring plate. Preferably, the coil spring is arranged between the spring retainer and the mounting plate. In particular, the coil spring is supported axially against the mounting plate and axially against the spring retainer.

[0023] In another possible design implementation of the invention, the spring assembly is operatively connected to the piston assembly, such that the piston assembly carries the spring assembly along during the actuation stroke and the return stroke. For example, the piston is positively and / or frictionally connected to the spring plate. Preferably, the piston presses against the spring plate when it executes the actuation stroke. This causes the spring plate and the spring plate attached to it to be carried axially against the preload of the coil spring. When the hydraulic pressure on the piston decreases, the piston is returned to its original position by the preload of the coil spring. In particular, the coil spring serves as a return mechanism.

[0024] One possible implementation of the invention provides that the multi-piston release system includes a force distribution device. Preferably, the force distribution device is designed to distribute the actuating force introduced into the brake device, particularly in the circumferential direction around the ring housing.

[0025] One aspect of the invention is that the friction plates of the friction plate assembly must be subjected to the actuating force as uniformly as possible across their surface area in order to avoid so-called hotspots, in particular partial overloading of the linings and friction surfaces of the friction plates and the associated underloading of other areas. The force distribution device advantageously allows the actuating force to be distributed across several points on the friction plates, thus preventing the formation of such hotspots.

[0026] In a preferred embodiment, the force distribution device is configured to introduce the actuating force into the braking device at several force application areas. Preferably, the force distribution device comprises the force application areas.

[0027] In another preferred embodiment, the number of force application areas is a multiple, e.g., twice or three times, of the number of pistons in the multi-piston release system. For example, when the pistons are hydraulically pressurized up to a certain limit pressure, the number of force application areas is twice the number of pistons. In particular, when the hydraulic pressurization of the pistons exceeds the limit pressure, the number of force application areas is three times the number of pistons.

[0028] A preferred embodiment of the invention provides that the force distribution device comprises a force distribution ring. Preferably, the force distribution ring is arranged coaxially and / or concentrically with respect to the main axis of the ring housing. Preferably, the force application areas are arranged on the force distribution ring, in particular on an upper surface of the force distribution ring pointing in the axial direction.

[0029] Another preferred embodiment of the invention provides that the force distribution device performs the actuating stroke together with the pistons. For example, the force distribution device is preferably arranged directly in the axial direction in front of the pistons. Preferably, the force distribution device is thereby brought into a contact position with the braking device when the pistons execute the actuating stroke. In particular, during the forward stroke, the pistons press against the force distribution device and move it into the contact position. Specifically, the actuating force of the pistons is introduced into the braking device by means of the force distribution device when the force distribution device is arranged in the contact position. Alternatively or optionally, the force distribution device can be operatively connected to the pistons for bringing it into the contact position and for transmitting the actuating force.

[0030] One possible implementation of the invention provides that each piston assembly is spatially and functionally assigned several force application areas of the force distribution device. Preferably, each piston assembly is assigned three force application areas. This means, in particular, that the force application areas are arranged axially in front of the respective spatially assigned piston assembly, so that they can multiply, in particular double or triple, the actuating force of the respective piston.

[0031] In one possible embodiment of the invention, force application areas are formed by teeth. Preferably, the teeth are arranged at intervals from one another on the force distribution ring. In particular, the teeth project axially from the top surface of the force distribution ring.

[0032] A preferred embodiment of the invention provides that some teeth have a first height and the other teeth have a second height, wherein the first height differs from the second height. Preferably, the first height is greater than the second height. In particular, some teeth are taller than the other teeth.

[0033] In one possible implementation of the invention, several teeth are spatially and functionally assigned to each piston assembly. In particular, a total of three teeth are spatially and functionally assigned to each piston assembly, one of which is shorter than the other two. Optionally, the tooth with the shorter height is arranged axially directly in front of the piston. Preferably, two teeth with the longer height are arranged at a distance on both sides of the tooth with the shorter height. Preferably, the force distribution device has a marking by means of which it can be correctly positioned relative to the actuating arrangement, in particular to the piston, as described above.

[0034] The spatial and functional arrangement of the teeth to the respective piston allows the actuating force to be advantageously distributed and harmonized, whereby it can be distributed to the two teeth or to all three teeth depending on the pressure of the hydraulic pressurization. In particular, the actuating force is distributed across the three teeth and thus harmonized when the hydraulic pressurization of the pistons exceeds the limit pressure.

[0035] In a preferred embodiment of the invention, the force distribution device has centering sections by means of which the force distribution device can be arranged concentrically relative to the ring housing. Preferably, the centering sections are arranged spaced apart from one another in the circumferential direction on the force distribution ring, projecting radially from it. For example, the centering sections are designed as toothed areas for engaging with corresponding teeth of a housing of the brake assembly and / or a transmission. In particular, the housing surrounds the wet chamber or is arranged in the wet chamber.

[0036] A braking device for a vehicle with the multi-piston release system according to the foregoing description and / or according to any one of claims 1 to 9 constitutes a further subject matter of the invention. The braking device comprises a braking assembly for generating a braking force. Preferably, the braking assembly is designed according to the foregoing description. In particular, the braking assembly comprises the friction plate assembly, which is preferably arranged coaxially and / or concentrically to the main axis. The friction plates of the friction plate assembly are inner plates, which are, for example, rotatably arranged, and outer plates, which are, for example, rotationally fixed. Preferably, the inner plates are supported by, for example, a rotatable inner plate carrier. Preferably, the friction plates are arranged and / or designed to be movable in the axial direction and in the opposite axial direction, in particular to be displaceable relative to one another.

[0037] In a preferred embodiment of the invention, the force distribution device, when arranged in the contact position, is arranged to contact the braking device in some or all force application areas, depending on the pressure of the hydraulic pressurization of the pistons. Preferably, two force application areas, in particular the two teeth with the first, greater height, contact the braking device when the hydraulic pressurization of the pistons is carried out with a pressure up to the limit pressure. In this case, the actuating force is distributed to the two teeth with the first height and transmitted to the braking device. If the limit pressure is exceeded during the hydraulic pressurization of the pistons, the pistons extend further and exert greater pressure against the force distribution device. This results in the second, lower-height tooth also contacting the braking device.In this case, the actuating force is distributed across the three teeth per actuating arrangement and transferred to the braking device.

[0038] Optionally, a transmission arrangement forms a further object of the invention. Preferably, the transmission arrangement comprises a transmission housing, a transmission, e.g., a planetary gear, and the braking device according to the preceding description and / or according to claim 10. Preferably, the transmission and the braking device are housed in the transmission housing. Preferably, the braking device, in particular the braking assembly, is arranged in the transmission housing such that it radially surrounds the transmission with respect to the main axis.

[0039] In one possible embodiment of the invention, the outer lamellae have external teeth with which they engage positively with a matching toothing in the gearbox housing, thus securing them against rotation and allowing them to move in the axial direction and in the opposite axial direction. Preferably, the inner lamellae have internal teeth with which they can mesh with a matching toothing of at least one component of the gearbox.

[0040] Further features, advantages, and effects of the invention will become apparent from the following description of preferred embodiments of the invention. These include: Figure 1 is a perspective top view in an axial direction of a multi-piston release system for actuating a braking device of a vehicle with several hydraulic actuating arrangements; Figure 2 is a perspective top view in the opposite axial direction of the multi-piston release system; Figure 3 is a section through a housing section of an annular housing of the multi-piston release system and through an actuating arrangement of the multi-piston release system; Figure 4 is a main housing of the annular housing of the multi-piston release system; Figure 5 is a perspective cross-section of the annular housing through the housing section and through the actuating arrangement; Figure 6 is a cross-section of the annular housing through the housing section and through the actuating arrangement.

[0041] Corresponding or identical parts are each provided with the same reference symbols in the figures.

[0042] In the Figure 1A perspective top view in an axial direction 6 of a multi-piston release system 1 is shown. Figure 2 shows a perspective top view of the multi-piston release system 1 in an axial opposite direction.

[0043] The multi-piston release system 1 can form a component of a brake device for a transmission assembly. The brake device comprises a brake assembly designed as a wet friction disc brake with a disc pack comprising a plurality of friction discs. The multi-piston release system 1 is designed as an activator device for the brake assembly. It can activate the brake assembly by transmitting an actuating force to generate a braking force.

[0044] The braking device can form part of a transmission assembly comprising a transmission housing filled with a wet fluid and a transmission, in particular a planetary gear set. It can be arranged together with the transmission within the transmission housing and brake the transmission there by means of the braking force of at least one component of the transmission. The transmission and the braking device can be arranged concentrically and / or coaxially with respect to a main axis 5 of the multi-piston release system 1, with the braking device radially surrounding the transmission.

[0045] The multi-piston release system 1 comprises an annular housing 2. The annular housing 2 has a main axis 5, which defines the axial direction 6. The annular housing 2 is formed in two parts in the axial direction 6. It consists of a main housing 24 and a housing cover 25. The main housing 24 and the housing cover 25 are arranged one above the other in the axial direction 6 and screwed together by means of a plurality of housing screws 7.

[0046] The main housing 24 has several, for example six, housing sections 16. The housing sections 16 are arranged at regular intervals from each other in the direction of rotation of the main housing 24 around the main axis 5.

[0047] The multi-piston release system 1 has several, for example six, hydraulic actuation arrangements 3. Each actuation arrangement 3 is assigned to exactly one housing section 16 and is incorporated into it section by section.

[0048] The main housing 24 has several pressure chambers 9 (see Figure 3 ) on. Each pressure chamber 9 is formed in one of the housing sections 16 and is assigned to the respective actuating arrangement 3. The pressure chambers 9 are fluidically separated from each other by a flow channel 4 (see Figures 4 to 6 ) connected so that they can be filled with a fluid, in particular a hydraulic fluid, which is different from the fluid of the wet room.

[0049] In the Figure 3 Figure 2 shows a sectional view through the ring housing 2 with the main housing 24 and with the housing cover 25, wherein a section line passes through a housing section 16 and through an actuating arrangement 3 associated with the housing section 16.

[0050] The actuating arrangement 1 comprises a piston assembly 17. The piston assembly 17 includes a piston 18. A guide body 33 is screwed to the piston 18. The piston 18 and the guide body 33 are arranged to be axially movable together in the pressure chamber 9. During axial movement, the guide body 33 guides the piston 18.

[0051] The actuating arrangement 1 comprises a first sealing device 19, a second sealing device 2, and a third sealing device 21. The first sealing device 19 and the second sealing device 21 are designed as O-rings and are fixedly arranged on the piston 18. They seal the piston 18 against the pressure chamber 9. The first sealing device 19 also functions as a sliding band, which facilitates the sliding of the piston 18 during axial movement. The third sealing device 21 is an axial-translational seal, which seals the pressure chamber 9 against the wet chamber in the gearbox housing.

[0052] The actuating arrangement 3 comprises a retaining plate 22, which is arranged axially 6 on the housing section 16 and screwed to it by means of two screws 23. When hydraulically pressurized by the fluid introduced into the pressure chamber 9, the piston 4 can execute an actuating stroke relative to the housing section 16 and the retaining plate 22 attached to it. This actuating stroke moves the piston 18 into an actuating position in which the brake device is actuated.

[0053] The actuating arrangement 3 has a spring assembly 26. The spring assembly 26 comprises a spring plate 27 and two spring plates 28. The spring plate 27 has a surface section 31 and two axial sections 29, which project from the surface section 31 in the opposite axial direction. The surface section 31 is arranged in the axial direction 6 in front of the retaining plate 22, extending parallel to it. The retaining plate 22 has two recesses 30 through which the axial sections 29 project in the opposite axial direction. The spring plates 28 are container-shaped and are attached at their ends to the axial sections 29 by a screw connection.

[0054] The spring assembly 26 comprises two coil springs 32. The coil springs 32 are arranged on the axial sections 29 between the retaining plate 22 and the spring plates 28. The coil springs 32 are supported at one axial end against the retaining plate 22 and at the other end against the spring plate 28.

[0055] The piston 18 is positively and / or non-positively connected to the surface section 31 of the spring plate 27. During the actuation stroke of the piston 18, the spring plate 27, together with the spring plates 28, is moved in the axial direction 6 against a preload of the coil springs 32. The coil springs 32 act as return elements, which return the piston 18 to its axial position when the hydraulic pressure is released.

[0056] The Figure 4Figure 1 shows the main housing 24 of the annular housing 2 in a perspective top view in the axial direction 6. The main housing 24 has the flow channel 4 by means of which the pressure chambers 9 in the housing sections 16 are fluidically connected. The flow channel 4 is designed as a one-piece, closed ring, which is arranged coaxially and / or concentrically to the main axis 5. The flow channel 4 is located in a parting plane between the main housing 24 and the housing cover 25 (see Figure 1). Figure 3 ) is introduced into the main housing 24 by machining. Due to the arrangement of the flow channel 4 in the parting plane, it can be manufactured easily and cost-effectively.

[0057] The main housing 24 has two fluid inlets 8 through which the fluid can be introduced into or drained from the flow channel 4 and through which the flow channel 4 and the pressure chambers 9 can be vented.

[0058] The main housing 24 has several, e.g., six, axial bores 34, which extend through the flow channel 4. The axial bores 34 open into the pressure chambers 9 of the respective housing sections 16 and into the fluid inlets 8. The pressure chambers 9 and the fluid inlets 8 are fluidically connected to the flow channel 4 via the axial bores 34. The main housing 24 has further bores 35 radially outside the flow channel 4 for the housing screws 7 (see Figures 1 and 2 ) and additional bores 36 for attachment to the gearbox housing when the multi-piston release system 1 is integrated into the brake device.

[0059] Referring to the Figure 3The multi-piston release system 1 has at least one channel seal 37 for sealing the flow channel 4. The at least one channel seal 37 is formed by a first O-ring 38 and a second O-ring 39. The housing cover 25 has an inner annular groove 40 and an outer annular groove 41, the inner annular groove 40 being arranged radially inside the outer annular groove 41. The first O-ring 38 is arranged in the inner annular groove 40 and the second O-ring 39 is arranged in the outer annular groove 41.

[0060] The Figure 5 Figure 1 shows a perspective cross-section of the ring housing 2 through the pressure chamber 9 of the housing section 16 and through the associated actuating arrangement 3. In the Figure 6 Figure 1 shows a cross-section of the ring housing 2 through the housing section 16 and the piston assembly 17.

[0061] The flow channel 4 is arranged radially between the inner annular groove 40 and the first O-ring 38 located therein, and the outer annular groove 41 and the second O-ring 39 located therein. The housing cover 25, which is screwed to the main housing 24, secures the O-rings 38 and 39 in their sealing position. This prevents the fluid in the flow channel 4 from escaping. The hydraulic pressure in the pressure chambers 9 for pressurizing the pistons 18 can thus be maintained.

[0062] Referring to the Figures 1, 2 , 5 and 6 The multi-piston release system 1 includes a force distribution device 10, by means of which an actuating force of the pistons 18 of the multi-piston release system 1 can be divided and thus harmonized depending on the hydraulic pressure.

[0063] The force distribution device 10 is arranged in the axial direction 6 directly in front of the pistons 18. It comprises a force distribution ring 11 and several force application areas 14 arranged thereon. The force distribution ring 11 is arranged concentrically and / or coaxially with the ring housing 2 with respect to the main axis 5. The number of force application areas 14 is a multiple of the number of pistons 18 present in the multi-piston release system 1. During the actuation stroke of the pistons 18, they press against the force distribution ring 11, so that the force distribution device 10, together with the pistons 18, is moved in the axial direction 6 and executes the actuation stroke.

[0064] When the multi-piston release system 1 is integrated into the brake device, the force application areas 14 can press against the friction plate assembly of the brake device in a contact position of the force distribution device 10, thereby introducing the actuating force of the piston 18 into it. The friction plates of the friction plate assembly are frictionally engaged by the introduction of the actuating force, thus generating a braking force to decelerate at least one component of the transmission.

[0065] The force application areas 14 are formed as teeth 12 with a first height and as teeth 13 with a second height. The first height is greater than the second height. There are several, e.g., a total of six teeth 13 with the second height and several, e.g., a total of twelve teeth 12 with the first height. The teeth 12 and 13 are spaced apart from each other in the direction of rotation around the main axis 5 on a top surface of the force distribution ring 11 oriented in the axial direction 6 and project from it.

[0066] The force distribution device 10 has several, e.g., three, centering sections 15 by means of which the force distribution device 10 can be arranged coaxially and / or concentrically to the main axis 5 and / or to the ring housing 2. The centering sections 15 are spaced apart from one another in the circumferential direction on the force distribution ring 11 and project radially from it. The centering sections 15 are designed as toothed areas by means of which the force distribution device 10 can engage with corresponding teeth of the gearbox housing when the multi-piston brake system is integrated into the brake assembly and the latter is arranged in the gearbox housing. During engagement, the force distribution device 10 is movable in the axial direction 6 and secured against rotation about the main axis 5.

[0067] The force distribution ring 11 is arranged and aligned relative to the housing ring 2 such that each piston assembly 3 is assigned a total of three teeth 12, 13. Specifically, each piston assembly 3 is assigned exactly two teeth 12 with the first, greater height and exactly one tooth 13 with the second, shorter height. The tooth 13 with the second height is located axially 6 directly in front of the piston 18. The two other teeth 12 with the first height are positioned at a distance to the side of the tooth 13 with the second height. A marking (not shown), e.g., in the form of an arrow, is provided on the force distribution ring 11. This marking facilitates and ensures the positioning of the force distribution ring 11 and the teeth 12, 13 relative to the ring housing 2 and the piston assemblies 3, as described above.

[0068] The distribution of the actuating force between teeth 12 and 13, which actuate the force application areas 14, depends on the pressure applied to the hydraulically pressurized piston 18. Up to a defined limit pressure, only the two teeth 12 associated with actuating arrangement 3, with the first, greater height, are pressed against the lamellar pack, thus transmitting a portion of the actuating force. This allows the actuating force transmitted by the piston 18 to be distributed between the two teeth 12 with the first height. If the limit pressure is exceeded, the piston 18 is moved further in the axial direction 6, pressing more strongly against the force transmission device 10. This also presses the second, shorter tooth 13, associated with actuating arrangement 3, against the lamellar pack, so that it too transmits a portion of the actuating force.In this case, the actuating force transmitted by the piston 18 is distributed across all three teeth 12, 13. This distribution and the resulting harmonization of the actuating force is advantageous in that it allows the actuating force to be applied as evenly as possible to one area of ​​the friction plates, thus preventing partial overloading of the linings and friction surfaces of the friction plates and the associated underloading of other areas of the friction plates. Reference symbol list

[0069] 1 Multi-piston release system 2 Ring housing 3 Actuating arrangement 4 Flow channel 5 Main shaft 6 Axial direction 7 Housing screws 8 Fluid inlets 9 Pressure chambers 10 Force distribution device 11 Force distribution ring 12 First-height teeth 13 Second-height teeth 14 Force application areas 15 Centering sections 16 Housing section 17 Piston assembly 18 Piston 19 First sealing device 20 Second sealing device 21 Third sealing device 22 Retaining plate 23 Screws 24 Main housing 25 Housing cover 26 Spring assembly 27 Spring plate 28 Spring plate 29 Shaft sections 30 Recesses 31 Surface section 32 Coil spring 33 Guide body 34 Axial bores 35 Other bores 36 Additional bores 37 Channel seal 38 First O-ring 39 Second O-ring 40 Inner ring groove 41 Outer ring groove

Claims

1. A multi-piston disengagement system (1) for a braking device of a motor vehicle, having an annular housing (2), wherein the annular housing (2) has a main axis (5), wherein the main axis (5) defines an axial direction (6), wherein the annular housing (2) has a plurality of housing sections (16), a plurality of pressure chambers (9) which can be filled and / or are filled with a fluid, and a flow channel (4), wherein a pressure chamber (9) is arranged in each housing section (16), wherein the pressure chambers (9) are fluidically connected to one another by means of the flow channel (4), having a plurality of hydraulic actuating arrangements (1), wherein each actuating arrangement (1) is assigned a housing section (16), wherein each actuating arrangement (3) has a piston assembly (17) with a piston (18), wherein the piston (18) is movably arranged in the pressure chamber (9) in the axial direction (6) and can perform an actuating stroke for the introduction of an actuating force into the braking device when hydraulic pressure is applied, wherein the annular housing (2) is formed in two parts in the axial direction (6) with a main housing (24) and with a housing cover (25) and characterized in that the actuating arrangements (3) are arranged at regular distances from one another in the direction of rotation around the annular housing (2).

2. The multi-piston disengagement system (1) according to claim 1, characterized in that the housing sections (16) and the flow channel (4) are arranged in or on the main housing (24).

3. The multi-piston disengagement system (1) according to claim 1 or 2, characterized in that the flow channel (4) is arranged in a separating plane of the main housing (24) and the housing cover (25).

4. The multi-piston disengagement system (1) according to any one of the preceding claims, characterized in that the flow channel (4) is designed in an annular shape and is arranged concentrically and / or coaxially to the main axis (5).

5. The multi-piston disengagement system (1) according to any one of the preceding claims, characterized in that the main housing (24) has a plurality of axial bores (34), wherein the axial bores (34) fluidically connect the flow channel (4) to the pressure chambers (9).

6. The multi-piston disengagement system (1) according to any one of the preceding claims, characterized in that the multi-piston disengagement system (1) has at least one channel seal (37) for sealing the flow channel (4), wherein the at least one channel seal (37) is at least one O-ring (38, 39) or at least one sealing plate.

7. The multi-piston disengagement system (1) according to claim 6, characterized in that the main housing (24) or the housing cover (25) has at least one annular groove (40, 41) concentric and / or coaxial to the main axis (5), wherein the at least one O-ring (38, 39) is arranged in the at least one annular groove (40, 41).

8. The multi-piston disengagement system (1) according to claim 6 or 7, characterized in that the at least one sealing plate is arranged between the main housing (24) and the housing cover (25).

9. The multi-piston disengagement system (1) according to any one of the preceding claims, characterized in that the main housing (24) and the housing cover (25) are connected to one another in a form-fitting and / or force-fitting manner.

10. A braking device for a transmission assembly of a motor vehicle with a braking device and with the multi-piston disengagement system (1) according to any one of the preceding claims, wherein the multi-piston disengagement system (1) forms an activator device for actuating the braking device.